High speed tele-printer



Aug. 22, 1961 Filed Nov. 6, 1957 Fig 2L JIN INOUE HIGH SPEEDTELE-PRINTER 3 Sheets-Sheet 1 1961 JlN [flour-z 2,997,542

7 HIGH SPEED TELE-PRINTER Filed Nov. 6, 1957 5 Sheets-Sheet 2 1961 JlNINOUE 2,997,542

HIGH SPEED TELE-PRINTER Filed Nov. 6, 1957 3 Sheets-Sheet 3 EELEE: LEIEE EEI ETJIIL United Smtes Patent Patented Aug 22, 1961 2,997,542 HIGHSPEED TELE-PRINTER Jin Inoue, 22 Nishimachi, Taito-ku, Tokyo-to, JapanFiled Nov. 6, 1957, Ser. No. 694,838 Claims priority, application JapanNov. 9, 1956 9 Claims. (Cl. 17828) This invention relates to a highspeed printer which is especially adapted for use in the art of printingtelegraphy as well as for calculating machines, automatic typewritersand recorders for measuring instruments.

The invention described herein concerns a printing telegraph ortele-printer, the principles of which are equally applicable to theother above named systems. Conventional printing telegraphs operate atpresent at about 450 to 500 letters per minute. This rate is consideredtoo slow for present day communications and with this invention greaterspeeds of, for instance, over one thousand letters per minute may beexpected. In order to reach such speeds intermittent and reciprocatingmotions of massive parts having large movements should be avoided. Thetype characters should approach the printing point on the paper, pressor print and withdraw therefrom at a constant speed while traveling inone direction. As there are some repetitions of the same characters inthe telegraphic messages, it is necessary that the type be quicklycirculated for the next printing operation.

As distinguished from the conventional rotary wheel printer in which thetype characters on the periphery thereof do not stop even for aninstant, since the wheel is kept under constant rotation, I haveprovided a rotary form of printer having the characters to be printedabout the periphery thereof and in which the character to be printed isstatic at the printing point. Any chosen character is selected to touchthe paper at the printing point to make an impression and immediatelyreturn to its original position during rotation of the printer. Duringpage printing, the relative feeds for space and line take place withoutshock.

For a more complete understanding of my invention, reference is had tothe description which follows and to the drawing, of which,

FIG. la is a view partly in section along the line 1--1 of FIG. 2,

FIG. lb is a View in elevation of a continuation of the lower part ofthe mechanism of FIG. 1a,

FIG. 2 is a sectional view of the tele-typewriter along lines C-C ofFIG. 1a,

FIG. 3 is a sectional view along line O'--O' of FIG. 1a,

FIG. 4 is a sectional view along line D-D of FIG. 3,

FIG. 5 is a developed plan View ,of the type rollers on the periphery ofthe type wheel, and

FIG. 6 is a developed plan view of the type rollers The type rollersterminate at their opposite ends in plungers 30, 31 of smaller diameter.The type rollers are capable of both rotation and axial sliding movementwithin the bearings 23 in the discs. Each type roller carries two ringsof type characters 1, 1, 1" and 2, 2', Z" axially spaced from each otherby a portion of the roller and a pinion gear 5 adjacent one end spacedfrom the lower ring of type 1, 1, 1" by a portion 4'. As shown, eachring of type comprises three type characters equally spaced about theaxis of the roller and upon rotation lie on the periphery of a cylinderhaving a diameter equal to the diameter of the pitch circle of thepinions 5, and all being equal.

The main shaft 16, 17 is supported at opposite ends in two bearings 34,34 which are fixed on a bed plate 70. On the same bed plate andintermediate the two bearings, is fixed another bearing 9 which supportsan internal gear 7 concentric with the main shaft 16, 17. The gear 7encircles the plurality of pinions 5 and meshes with all of the pinionsat the portions of their peripheries furthest from the shaft 16, 17 toprovide a planetary gear arrangement.

If the internal gear 7 is fixed and has a pitch circle 6 of a diameterwhich is n times that of a pinion 5, where n is an integral number, thenevery pinion returns to its original phase position after n revolutionsduring one revolution of the main shaft 16, 17 It is obvious that eachpinion 5 will remain in pure rolling contact with the internal gear 7,with its own pitch circle within the pitch circle of the internal gear.A predetermined point on the pitch circle of any pinion 5 coincides witha fixed point 0" on the pitch circle 6 of the internal gear when thepinion rolls over the fixed point 0" at every revolution of the mainshaft. See FIG. 2.

If new a type character such as 2 is provided at a certain point on theperiphery of each roller coinciding with point 0" but somewhat radiallyinward of the pitch circle 6 as at fixed point 0 in FIG. 3, then thischaracter will always coincide with the fixed point at every revolutionof the main shaft 16, 17. If a paper surface 8-4 is provided at thefixed point 0- supported at its rear by a platen of elastic material83*, then the type at the certain point on each roller will make animpression on the paper as it rolls thereover at each revolution of themain shaft. The type characters may be inked in any convenient manner asis conventionally done in typewriters or tele-printers as by an inkingribbon, pad, belt or roller, etc. provided adjacent the paper surface atthe fixed point 0.

As can be seen from FIG. 3, when the type carrier or main shaft 16, 17is rotated in a counterclockwise direction, the rollers carrying thetype-characters are translationally moved in the same direction.However, due to meshing of the pinions 5 with the internal fixed gear 7,the type rollers are individually rotated about their individual axes ina clockwise direction. As a type-character such as 2 approaches theprinting positions 0 it is relatively static, since its linear velocityin one direction (upwardly in FIG. 3) due to rotation about its ownaxis, is equal to its linear velocity in the other direction (downwardlyin the figure) by reason of its translational movement about the axis ofshaft 16, 17. Thus, the problem of high speed printing is met by havingthe type-characters approach the printing point 0 on the paper in onedirection, press the letter or figure onto the paper while momentarilyrelatively stationary and withdraw from the printing point, while stilltravelling at constant speed in the same direction.

As shown in FIG. 1a, the rings of type '1, 1, 1" and 2, 2' 2" on eachtype roller are normally spaced on either side of a printing planetransverse to the axes of the rollers and passing through the printingpoint 0. When a type-character is to be printed in response to a signalfrom a telegraphic communication system for each revolution of the typewheel, a selected type roller is raised or lowered to bring a line oftype into the printing plane. .The mechanism forthus selecting the lineof type will .now' be described. To the outer-surfaces of the discs 20and 21 are secured a plurality of cylinders concentric opposite sides ofthe plane -0 passing through the printing point by compressed airsupplied by a pipe 29 to the bottoms of the lower cylinder bores 28, toslightly raise the type rollers from their lowermost positions. Thepipes 29 are connected to radial slots 22 in the discs 20 and 21 whichcommunicate with a bore 19 extending longitudinally through the mainshaft 16, 17. An annular groove 36" in the bearing 34 suppliescompressed air to the longitudinal bore 19 through a transverse opening19'.

At the shoulder provided between the reduced diam- ,eter cylinder bore27 and cylinder 28 is an opening with which a pressure pipe 26communicates at one end. The

pressure pipe 26 communicates at its other end wtih a receiving hole 35through a pressure hole 25 in the main shaft 17 as seen in FIG. 4. Thereceiving hole opens into an annular groove 36 in the bearing 34 and thegroove 36 has a communication port 37 that opens at the midpoint of avalve cylinder 38 as can be seen in FIGS. vvla and 4. The valve cylinder38 has an exhaust port 37' at one end and a pressure port 40- at itsother end and receives a piston valve 41, 42, 43, the parts designated41 and 43 being pistons and the part 42 a waist portion connecting thepistons and having an annular space there- .about between it and theinner wall of the cylinder 38 for flow of compressed air.

The above described arrangement is provided for each of the typerollers.

Each piston is provided with a neck portion 44 and a head portion 45,there being a coil spring 46 between the head '45 and the adjacentsurfacec of the bearing 34 to bias the valve body to a position in whichthe port 37 communicates with the exhaust port 37. One half of theplurality of piston valves each have a tail portion 47 pivoted at itsend to a tongue 58 of a respective armature 60 of an electromagnet 52',53' in a lower tier as shown in FIG. 4. The other half of the pluralityof piston valves each have a hook portion 48 at its end inserted in anopening at the end of tongue 59 of a respective armature 60 of anelectromagnet in the upper tier as at 2, 53. The hooked and tailedpiston valves are alternately positioned in the valve cylinders 38 whichare bored through the bearing body 34, 34 along both sides of the mainshaft 16, 17 and in which the valves fit with an air-tight slidahleengagement.

Both bearings 34 are fixed indirectly on the bed plate 70 throughsupports 34' mounted on pedestal blocks 34". The pedestal blocks areprovided with upper and lower horizontal beams 68 and 69, respectively.The upper tier of electromagnets 51 57 and 61 67 is carried by thehorizontal beams 68 and the lower tier 51 57' and 61' 67' is carried bythe lower beams 69. She group of magnets 51-58 is supported by the beamson one side of the line O-O' and a second group 6168' on the other sideof the line. As shown in FIGS. 1a and lb there are fifteen type rollers,fifteen electromagnets on each side of the line OO and thirty typerings. Each electromagnet is individually controlled by a circuit andcorresponds to a type ring on a respective type roller.

When an electromagnet, as for example 53 in FIG. 4, is selectivelyexcited by a signal current, its armature 60 is moved to pull down apiston valve by engagement of tongue 59' with hook 48 to connectpressure port 40 with a communication port 37. The compressed airissuing from port 40 reaches the cylinder 27 (FIG. la) pushes thespindle 3 to position the: type ring 2, 2 2" to coincide with the lineOO' through the printing point. The selected type-character willtherefore roll over the printing point 0 on the paper 84 to impress orprint such character. When the selected type ring coincides with theprinting plane, the force of the spindle thrust is decreased due to theshoulder portion on the spindle 3" reaching the .point is to prevent thefrictional resistance induced by thrust from acting between the oppositeshoulder on spindle 3 and bottom of cylinder 28 and between the end ofplunger 31 and the bottom of cylinder 27. 7 When the excitation of themagnet 53 is discontinued, the pulled armature 60" is released to permitthe piston valve to return to its original position by spring 44 actingon the head '45. This closes the pressure port 40 and connects thecommunication port 37 with the exhaust port 37 The type ring which hadbeen in the printing plane then returns to its original position to oneside thereof. In the same manner as hereinabove described, any one ofthe type rollers may be moved to position the selected type ring in theprinting plane in accordance with a selecting signal from thetelegraphic communication circuit. The selected electromagnet mustreceive the signal early enough in each revolution of the main shaft 16,17 to allow the desired type roller to move by the compressed air tobring its type ring into the proper position for printing. The time thatis needed to adjust a piston valve is constant, but the air passages toeach cylinder are of various lengths and it is estimated that about 0.01second is needed to bring a type ring to the printing plane after itspiston valve is opened. As shown in FIG. 6, the longest time allowed forthe first type roller in the array to bring the type ring into theprinting position, after initiation of :an electrical signal, is S andthe other type rollers are allowed longer times due to theirpositionalorder in the space P. Therefore, the length of the path 37,35, 25, 26, 27 for the compressed air must be shortest for the firsttype roller and successively longer for the following rollers. Eachcharacter type that is selected must be steady at the printing point inorder to make a clear impression, so that all of the above describedmotions should be completed before the roller that supports the selectedcharacter reaches the printing point in every revolution of the mainshaft. The time needed for moving each piston valve may be overlappedwith the preceding revolution of the main shaft 16, 17 which is constantand uniform about all-the valves.

The shifting action to change letters or figures from the lower case tothe uppercase as in conventional typewriters or teletype systems isincluded by this invention. However, the reciprocating motions for thisoperation together with the resulting shock and noise, especially athigh speeds, are avoided by the adoption of a circular shift ashereinafter described. For this purpose, each is n times the diameter ofthe pinions so that when the internal gear 7 turns l/n revolution, thefirst type characters 1, 2 the second type 1', 2 and third type 1", 2"return to their original positions after one rotation of the pinion 5and its associated type roller. In other words, they remain in theiroriginal phase. If the internal gear 7 turns /311 revolution from apredetermined point, the pinion 5 will be rotated /3 revolution so thatthe second typel', 2' appears at the point where the first type appearedpreviously. This shifting action is analogous to the case shift of aconventional typewriter. Similarly, the next /sn revolution of the gear7 turns the pinions another /3 revolution and the third type 1" and 2"appear at the original position of the first type.

In order to carry out the shifting operation of the various type asabove described, the outer periphery gear 7 is provided with gear teethto form an external gear 8 about its periphery and which meshes with apinion 10 having a diameter which is 1/ n that of the external gear 8and has l/n teeth as compared to that of the gear 8. The pinion 10 issupported in bearings 9 and 9 by a shaft 14 on which are secured threeradially extending pins 11, 12 and 13. The pins are arcuately spacedabout the axis of the shaft by 120 and are axially spaced. A shifterframe 80 is fixed to the bed plate 70 and is provided with a pair ofparallel arms which supports a horizontal shaft 14'. Pivotally mountedabout the shaft are three setting hooks 71, 72, 73 in the form oflevers, the lower arms of which each supoprt an armature 81 of arespective electromagnet. The top surface of each of the setting hooksis flattened in a horizontal plane and each lever is biased by a tensionspring 78 to maintain the flattened surface clear of the path of thephase pins 11, 12 and 13. The tension springs 78 are adjustable by nuts79 which are friotionally held against turning by members 79.

Shifter magnets 91, 92 and 93 are fixed on the shifter frame 80, one foreach setting hook, and face a respective armature 81. Each setting hookhas a notch or shoulder 71 toward the rear portion of its upper end, asshown in FIG. 2, and a movable projection 75 pivoted at 76 to the bodyof the setting hook and capable of turning forwardly but stopped fromturning rearwardly by a stop pin 75'. A common check pawl 74 pivoted at74' on the top 15 of the shifter frame 80 is pulled down toward thenotches in the setting hooks by light springs, not shown. When a shiftermagnet, for example 91, is energized it pulls its armature 81 to projectthe setting hook 71 into the path of a phase pin 11, the hook beingprevented from moving rearwardiy by engagement of the pawl 74 within thenotch 71'. The rotation of shaft 14 and pinion 10 is thus stopped byengagement of pin 11 with setting hook 71. If the external gear 8 andpinion 10 are so engaged that the first type 1, '2 are in such phasethat they may be positioned at the printing point when the typt rolleris moved to the proper position, they will remain in that phase as longas phase pin 11 is caught by setting hook 71. This condition is providedas described above, by the excitation of shifter magnet 91 and thiscondition continues until any other shifter magnet is excited.

When another shifter magnet is excited, 92 for example, it attracts itsarmature to project the setting hook 72 into the path of the phase pin12. The projection 75 of the setting hook 72 raises the check pawl 74 asit moves forwardly, to move it away from the notch or shoulder 71 torelease the previously moved setting hook 71 to allow it to moverearwardly. The phase pin 11 is fireed for revolution with the shaft 14,but the latter is stopped as soon as the phase pin 12 is caught on thesetting hook 72. The shaft 14 will have turned sufiiciently to allow theinternal gear 7 to turn Van revolution before it is stopped by the phasepin 12 catching on the setting hook 72. The pinions 5 of the typerollers are translated about the axis of shaft 16, 17 at this timetogether with internal gear 7,

but are not relatively rotatedabout their axes. 18y the time the gear 7is stopped against rotation, the angular phase position of the pinionsand type rollers relative to the internal gear 7 has changed by 120 sothat the second type 1, 2 can be positioned at the printing point.

When the third shifter magnet 93 is energized by a shifting signal, thesetting hook 73 is projected into the path of phase pin 13 and raisesthe common check pawl 74 to release the previously projected settinghook for return movement by. its spring. In the same manner as describedabove, the third type 1", 2" will be positioned at the printing point 0.It now becomes possible to bring any letter or figure selected by asignal up to the printing point regardless of which phase of the typerings the letter or figure belongs to. The number and spacing of thephase pins together with the number of setting hooks and magnets are ofcourse dependent on the number of type characters in a type ring.

The machine of this invention can be provided for printing on tape or inpage style. In order to print page style at high speed, however, themotion of the carriage return with its consequential disadvantages ofhigh resistance and shock due to movements of a large mass at greatspeed, should be avoided. Spiral printing is therefore provided as asubstitute for the conventional spacing and carriage return movementswhere page printing is desired. For this purpose, both marginal edges84", 84" of the paper which are to remain unprinted and which correspondto the space S, are folded back at right angles and the paper woundabout a disk-like platen 83 with the folded margins inserted into aradial slot as shown in FIG. la. The platen 83 is mounted on a centershaft 82 which rotates about an axis transverse to that of shaft 16, 17.At one side of the platen 83, an inner cylindrical guide 85 is fixed onthe shaft 82 concentric therewith. An outer guide 86 formed of anelongated metal sheet somewhat wider than the paper sheet 84 has bothedges folded back through 180 to form a narrow groove at each side toguide the edges of the paper 84. The outer guide 86 surrounds the innerguide 85 and is fixed to the shaft 82 and platen 83. At some distancefrom its lower end, the margins of the outer guide equal in width to thefolded margins of the paper, are folded along lines parallel to thegrooves and with an increasing angle of fold up to as it approaches theplaten. The flat portion of the sheet between the folds is rolled intoconical form to complete a circular cross-section to surround the innerguide adjacent the platen, but the lower end is left flat.

There are several pairs of feed rollers at a level beneath the platen soas to face and press against each other from within the inner guide andfrom without the outer guide. The rollers are rotated respectively withthe revolutions of the shaft 16, 17 while revolving about the shaft 82to feed the paper just the height of one lineduring one revolution ofthe platen. On the upper side of the platen are an inner cylinder 87 andan outer cylinder 88 to guide the paper in a cylindrical form that isfed up from the platen 83 and protects the paper from deflection againstthe type wheel and consequent mutilation due to the high speed ofrotation of the wheel. The outer cylinder 88 may terminate in a sharpedge which acts as a cutting knife and is fixedly secured on the bedplate 70. The whole face of the paper that appears about the platenbetween the upper and lower guides is prepared for printing at all timessince it cor responds to the full length of a lettering line.

It is important to provide quick line feed at the end of each line wherehigh-speed printing is desired and this can be done by providing spiralprinting with the apparatus of this invention. The spacing or horizontalfeed is provided by the revolution of the platen and the line feed orvertical feed of the paper isdone during the revolution of the platenuniformly and slowly. The result is that beginning of one line connectswith the .end of a preceding line at the folding edges of the paper. Toprovide a printed spiral line, the paper should be fed with a slightinclination to produce the-spiral angle of thelettering line. Thus theinner and outer guides 85 and 86-should be slightly in spiral form tocorrespond to the angle of the lettering line. Also, the shaft of theplaten 82 is inclined with respect to the plane through the printingpoint at an angle which is equal to and-opposite to the angle of thespiral in order to obtain upright letter printing.

If the letter spacing is to be made after the printing of each letter orfigure, as in conventional typewriters, this can be provided for byintermittent rotation of the platen 83, so that the paper remains staticat each printing stroke. The printing speed, however, with such anarrangement, may be slower than 1000 words per minute. The letters andfigures on the type rollers will be distributed as shown in thedeveloped view of FIG. 5.

But where high speed printing of over 1000 letters per minute isdesired, the intermittent rotations of the platen 83 is not favorable tothe smooth operation or durability of the apparatus. It is moreadvantageous to rotate the platen and its parts at a uniform speedrelatively to the revolutions of main shaft 16, 17. Where the papermoves at uniform speed in a fixed direction throughout the printing of amessage, any one character type selected by a signal must roll over theprinting point on the paper in a direction which is along the hypotenuse0-0 of a night angled triangle, as in FIG. 6. Such triangle has a lengthof one circumference of a circle circumscribed by the type Wheel and alength of one letter space as the base. The circumscribed circlereferred to is one described by a point at the outermost end of thecommondiameter of the type wheel and type ring corresponding to thediameter of the pitch circle of gear 6. Thus, the surface of a typecharacter selected by a signal is static relative to the paper at theirtangent point when the type ring rolls over the printing point 0.

Due to the positional order of the type rollers 4 about the axis of theshafet 16, 17, each type roller lags by a different time increment inreaching the printing position after the last character has made animprint and may cause a disarrangement of the letter spacing. Tocompensate for this, the type rings are each oifset a different amountfrom the plane OO including the printing point and lie along the line Q,Q which is inclined from the plane OO' to provide one space lengthbetween the first and last type rollers of the array during onerevolution of the type wheel. The distance S in FIG. 6 corresponds tothe time required to place the type rollers in the printing position andthe remaining distance P corresponds to the time in which all of therollers are rotated about the axis of shaft 16, 17 and during which timea type character on one o fthe rollers has made an imprint on the paper84. The whole distance S plus P is equal to one circumference of thecircle transcribed by the rotatable type wheel.

The main shaft 16, 17 is sheathed by a hollow shaft 18 at each side ofthe type wheel in order to cover the air passages 25 tightly and protectthem. Toward each end of the main shaft is mounted a thrust collar 33"to prevent axial movement of the type wheel and a heavy flywheel 89 isfixed adjacent one end of the shaft to equalize the reactions of theshifting and phase selecting motions and to maintain the rotating partsat a constant speed. A flywheel may be secured to the one of the shaftto drive it from a motor.

From the description above, the following characteris'ticsof'the'apparatus may be recognized: (1) the printing arid paper feedingmovements are accomplished duririg constant rotation of the main shaftat high speed; (2) the case shifting of the letters is accomplishedduring a partial rotation of the type rollers; (3) the selection of thecharacterto be printed is provided by the axial reciprocating motion ofthe type-roller which is of light construction and has a short movementindependently of the rotation ofthe type wheel; and (4) the capabilitiesof continuous high speed printing-without endangering the durability ofthe parts. In the practical op eration of the teleprinter apparatusherein disclosed it must be combined with. a translator which is coupledto a distant transmitter and in operative synchronism there'- with.

Having thus described the invention, what is claimed 1. A high-speedautomatic typewriter comprising, a carrier rotatable about an axis, anarray of type-characters equally radially spaced from and concentricwith the axis, means mounting each of said characters on the carrier forrotation about individual axes parallel to the axis of the carrier,means for simultaneously rotating the carrier in one direction and thetype-characters in an opposite direction such that the linear velocityof the characters due to rotations about the axis of the carrier andtheir individual axes are equal, and a sheet having a surface supportedin a predetermined plane tangent to the periphery of a cylinderdescribed by the rotation of the characters about the axis of thecarrier, to receive an imprint thereof.

2. A high-speed automatic typewriter in accordance with claim 1, inwhich the means for simultaneously rotating the carrier and charactersincludes a driven gear secured to and rotatable with each type-characterand a fixed driving pinion commonly engageable with each of the drivengears, whereby rotation of the carrier causes rotation of thecharacters. 7

3. A high-speed automatic typewriter in accordance with claim 2, inwhich each type-character is supported on the periphery of a shaft overwhich it extends for a small arcuate distance, the driven gears being ofequal diameter and so related to the diameter of the fixed pinion thatthe characters are successively positioned at the predetermined plane byrotation of the carrier.

4. A high-speed automatic typewriter in accordance with claim 1, inwhich the type-characters are individually mounted for axial movementfrom a first axial inoperative position to a second axial printingposition and means for selectively moving a character axially to theprinting position to provide an imprint on the surface of the sheet inthe tangent plane and at said second axial position.

5. A high-speed automatic typewriter in accordance with claim 4, inwhich each of the type-characters is individually secured to theperiphery of a shaft, cylindrical hearings in the carrier for supportingthe shafts for axial and rotatable movements, the bearings at least atone end of the shafts being provided with inlet openings, a source ofcompressed air, and means for operatively connecting the inlet openingof a selected cylinder to the source of compressed air to move theshaft. axially for positioning the character at said second axialprinting position.

6. A high-speed automatic typewriter. in accordance with claim 4,including a circular platen mounted for rotation on an axis transverseto that of the carrier for movably supporting said sheet in thepredetermined tangent plane and printing position.

7. A high-speed automatic typewriter in accordance with claim 6,including means operated by the carrier upon each revolution thereof formoving the sheet supported on the platena distance corresponding to adesired spacing between successive characters to be printed.

8. A high-speed automatic typewriter in accordance with claim 6,including a radial slot in said platen to receive the ends of the sheetwrapped about the platen whereby the sheet forms an endless web,"meansoperated by the carrier during its rotation for continuously moving theplaten about its axis at a'speed to receive imprints of succesivecharacters, the axial printing positions of successive characters in thearcuate array varying in ac- 9 cordance with their arcuate distance froma predetermined character in the direction of rotation of the carrier,whereby successive selected characters printed respectively at eachrotation of the carrier are equally spaced.

9. A high-speed automatic typewriter in accordance with claim 6,including a radial slot in said platen to receive the ends of the sheetwrapped about the platen whereby the sheet forms an endless web, meansoperated by the carrier during its rotation for continuously moving theplaten about its axis at a speed to receive imprints of successivecharacters, the axial printing positions of successive characters in thearray varying in accordance with their arcuate distance from apredetermined character in the direction of rotation of the carrier,whereby successive selected characters printed respectively at eachrotation of the carrier are equally spaced, and means for simultaneouslymoving the sheet axially at a predetermined uniform rate to elfectcontinuous spiral lines of printing.

References Cited in the file of this patent UNITED STATES PATENTS

